SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Timothy Leary

790

Lysergic acid diethylamide (LSD) is the prototypical psychedelic drug, but its effects on the human brain have never been studied before with modern neuroimaging. Here, three complementary neuroimaging techniques: arterial spin labeling (ASL), blood oxygen level-dependent (BOLD) measures, and magnetoencephalography (MEG), implemented during resting state conditions, revealed marked changes in brain activity after LSD that correlated strongly with its characteristic psychological effects. Increased visual cortex cerebral blood flow (CBF), decreased visual cortex alpha power, and a greatly expanded primary visual cortex (V1) functional connectivity profile correlated strongly with ratings of visual hallucinations, implying that intrinsic brain activity exerts greater influence on visual processing in the psychedelic state, thereby defining its hallucinatory quality. LSD’s marked effects on the visual cortex did not significantly correlate with the drug’s other characteristic effects on consciousness, however. Rather, decreased connectivity between the parahippocampus and retrosplenial cortex (RSC) correlated strongly with ratings of “ego-dissolution” and “altered meaning,” implying the importance of this particular circuit for the maintenance of “self” or “ego” and its processing of “meaning.” Strong relationships were also found between the different imaging metrics, enabling firmer inferences to be made about their functional significance. This uniquely comprehensive examination of the LSD state represents an important advance in scientific research with psychedelic drugs at a time of growing interest in their scientific and therapeutic value. The present results contribute important new insights into the characteristic hallucinatory and consciousness-altering properties of psychedelics that inform on how they can model certain pathological states and potentially treat others.

Concepts: Nervous system, Brain, Human brain, Cerebral cortex, Lysergic acid diethylamide, Psychedelic drug, Psychedelics, dissociatives and deliriants, Timothy Leary

453

The classical serotonergic psychedelics LSD, psilocybin, mescaline are not known to cause brain damage and are regarded as non-addictive. Clinical studies do not suggest that psychedelics cause long-term mental health problems. Psychedelics have been used in the Americas for thousands of years. Over 30 million people currently living in the US have used LSD, psilocybin, or mescaline.

Concepts: Health care, Psychology, Clinical trial, Serotonin, Mental disorder, Psychoactive drug, Controlled Substances Act, Timothy Leary

20

A recent large population study of 130,000 adults in the United States failed to find evidence for a link between psychedelic use (lysergic acid diethylamide, psilocybin or mescaline) and mental health problems. Using a new data set consisting of 135,095 randomly selected United States adults, including 19,299 psychedelic users, we examine the associations between psychedelic use and mental health. After adjusting for sociodemographics, other drug use and childhood depression, we found no significant associations between lifetime use of psychedelics and increased likelihood of past year serious psychological distress, mental health treatment, suicidal thoughts, suicidal plans and suicide attempt, depression and anxiety. We failed to find evidence that psychedelic use is an independent risk factor for mental health problems. Psychedelics are not known to harm the brain or other body organs or to cause addiction or compulsive use; serious adverse events involving psychedelics are extremely rare. Overall, it is difficult to see how prohibition of psychedelics can be justified as a public health measure.

Concepts: Psychology, Mental disorder, Bipolar disorder, Suicide, Parasuicide, Lysergic acid diethylamide, Lysergic acid, Timothy Leary

16

Lysergic acid diethylamide (LSD) is a potent serotonergic hallucinogen or psychedelic that modulates consciousness in a marked and novel way. This study sought to examine the acute and mid-term psychological effects of LSD in a controlled study.

Concepts: Lysergic acid diethylamide, Lysergic acid, Ergot, Timothy Leary, LSD

9

Psychedelic drugs such as lysergic acid diethylamide (LSD) were used extensively in psychiatry in the past and their therapeutic potential is beginning to be re-examined today. Psychedelic psychotherapy typically involves a patient lying with their eyes-closed during peak drug effects, while listening to music and being supervised by trained psychotherapists. In this context, music is considered to be a key element in the therapeutic model; working in synergy with the drug to evoke therapeutically meaningful thoughts, emotions and imagery. The underlying mechanisms involved in this process have, however, never been formally investigated. Here we studied the interaction between LSD and music-listening on eyes-closed imagery by means of a placebo-controlled, functional magnetic resonance imaging (fMRI) study. Twelve healthy volunteers received intravenously administered LSD (75µg) and, on a separate occasion, placebo, before being scanned under eyes-closed resting conditions with and without music-listening. The parahippocampal cortex (PHC) has previously been linked with (1) music-evoked emotion, (2) the action of psychedelics, and (3) mental imagery. Imaging analyses therefore focused on changes in the connectivity profile of this particular structure. Results revealed increased PHC-visual cortex (VC) functional connectivity and PHC to VC information flow in the interaction between music and LSD. This latter result correlated positively with ratings of enhanced eyes-closed visual imagery, including imagery of an autobiographical nature. These findings suggest a plausible mechanism by which LSD works in combination with music listening to enhance certain subjective experiences that may be useful in a therapeutic context.

Concepts: Brain, Magnetic resonance imaging, Psychiatry, Emotion, Lysergic acid diethylamide, Lysergic acid, Psychedelics, dissociatives and deliriants, Timothy Leary

6

There is renewed interest in the therapeutic potential of psychedelic drugs such as lysergic acid diethylamide (LSD). LSD was used extensively in the 1950s and 1960s as an adjunct in psychotherapy, reportedly enhancing emotionality. Music is an effective tool to evoke and study emotion and is considered an important element in psychedelic-assisted psychotherapy; however, the hypothesis that psychedelics enhance the emotional response to music has yet to be investigated in a modern placebo-controlled study.

Concepts: Emotion, Lysergic acid diethylamide, Lysergic acid, Ergot, Psychedelic drug, Psychedelics, dissociatives and deliriants, Timothy Leary, Psychedelic music

4

Plant-based psychedelics such as psilocybin have an ancient history of medicinal use. After the first English-language report on LSD in 1950, psychedelics enjoyed a short-lived relationship with psychology and psychiatry. Used most notably as aides to psychotherapy for the treatment of mood disorders and alcohol dependence, drugs such as LSD showed initial therapeutic promise before prohibitive legislature in the mid-1960s effectively ended all major psychedelic research programmes. Since the early 1990s, there has been a steady revival of human psychedelic research: last year saw reports on the first modern brain imaging study with LSD and 3 separate clinical trials of psilocybin for depressive symptoms. In this Circumspective piece, Robin Carhart-Harris and Guy Goodwin share their opinions on the promises and pitfalls of renewed psychedelic research, with a focus on the development of psilocybin as a treatment for depression.Neuropsychopharmacology accepted article preview online, 26 April 2017. doi:10.1038/npp.2017.84.

Concepts: Alcoholism, Serotonin, Clinical psychology, Psychiatry, Psychoactive drug, Psychedelic drug, Psychedelics, dissociatives and deliriants, Timothy Leary

1

Psychedelic drugs, such as lysergic acid diethylamide (LSD), mescaline, and psilocybin, exert profound effects on brain and behavior. After decades of difficulties in studying these compounds, psychedelics are again being tested as potential treatments for intractable biomedical disorders. Preclinical research of psychedelics complements human neuroimaging studies and pilot clinical trials, suggesting these compounds as promising treatments for addiction, depression, anxiety, and other conditions. However, many questions regarding the mechanisms of action, safety, and efficacy of psychedelics remain. Here, we summarize recent preclinical and clinical data in this field, discuss their pharmacological mechanisms of action, and outline critical areas for future studies of psychedelic drugs, with the goal of maximizing the potential benefits of translational psychedelic biomedicine to patients.

Concepts: Pre-clinical development, Psychoactive drug, Controlled Substances Act, Lysergic acid diethylamide, Lysergic acid, Psychedelic drug, Psychedelics, dissociatives and deliriants, Timothy Leary

0

Classic hallucinogens (e.g. psilocybin and LSD) have substantial effects on perception, cognition, and emotion that can often be psychologically challenging, however we know very little regarding the source of significant individual variability that has been observed in the frequency and intensity of challenging experiences (i.e. “bad trips”) with psychedelics. Previous clinical and observational literature suggests that there may be an association between neuroticism and challenging psychedelic experiences.

Concepts: Psychology, Cognition, Philosophy of science, Knowledge, Psychedelic drug, Psilocybin mushrooms, Timothy Leary, Bad trip

0

Anxiety and depression are some of the most common psychiatric symptoms of patients suffering with life-threatening diseases, often associated with a low quality of life and a poor overall prognosis. 5-HT2A-receptor agonists (serotonergic hallucinogens, “psychedelics”) like lysergic acid diethylamide (LSD) and psilocybin were first investigated as therapeutic agents in the 1960s. Recently, after a long hiatus period of regulatory obstacles, interest in the clinical use of these substances has resumed. The current article provides a systematic review of studies investigating psychedelics in the treatment of symptoms of existential distress in life-threatening diseases across different periods of research, highlighting how underlying concepts have developed over time. A systematic search for clinical trials from 1960 to 2017 revealed 11 eligible clinical trials involving a total number of N=445 participants, of which 7 trials investigated the use of lysergic acid diethylamide (LSD) (N=323), 3 trials investigated the use of psilocybin (N=92), and one trial investigated the use of dipropyltryptamine (DPT) (N=30). The 4 more recent randomized controlled trials (RCTs) (N=104) showed a significantly higher methodological quality than studies carried out in the 1960s and 1970s. Evidence supports that patients with life threatening diseases associated with symptoms of depression and anxiety benefit from the anxiolytic and antidepressant properties of serotonergic hallucinogens. Some studies anecdotally reported improvements in patients´ quality of life and reduced fear of death. Moreover, low rates of side effects were reported in studies that adhered to safety guidelines. Further studies are needed to determine how these results can be transferred into clinical practice.

Concepts: Epidemiology, Clinical trial, Randomized controlled trial, Pharmaceutical industry, Serotonin, Lysergic acid diethylamide, Lysergic acid, Timothy Leary